SSRAM
AS5SS256K18
Austin Semiconductor, Inc.
256K x 18 SSRAM
PIN ASSIGNMENT
Synchronous Burst SRAM,
(Top View)
Flow-Through
FEATURES
100-pinTQFP
• Fast access times: 8, 10, and 15ns
• Fast clock speed: 113, 100, and 66 MHz
• Fast clock and OE\ access times
• Single +3.3V +0.3V/-0.165V power supply (VDD
• SNOOZE MODE for reduced-power standby
• Common data inputs and data outputs
• Individual BYTE WRTIE control and GLOBAL WRITE
• Three chip enables for simple depth expansion and address
pipelining
• Clock-controlled and registered addresses, data I/Os and
control signals
100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81
NC
NC
NC
DDQ
VSS
NC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
SA
NC
NC
VDD
VSS
NC
DQPa
DQa
DQa
VSS
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
)
V
Q
NC
DQb
DQb
VSS
VDD
Q
DQb
DQb
VSS
VDD
Q
DQa
DQa
VSS
NC
VDD
ZZ
VDD
NC
VSS
DQb
DQb 19
DDQ
VSS 21
DQb 22
DQb
• Interally self-timed WRITE cycle
• Burst control pin (interleaved or linear burst)
• Automatic power-down
DQa
DQa
V
20
VDD
VSS
DQa
DQa
NC
NC
VSS
VDD
NC
NC
NC
Q
• Low capacitive bus loading
• Operating Temperature Ranges:
23
- Military -55oC to +125oC
DQPb 24
NC 25
- Industrial -40oC to +85oC
VSS
VDD
26
27
Q
Q
NC 28
NC
NC 30
OPTIONS
• Timing
MARKING
29
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
7.5ns/8ns/113 MHz
8.5ns/10ns/100 MHz
10ns/15ns/66 MHz
• Packages
-8*
-9
-10
**pins 42,43 reserved for future address expansion for 8Mb, 16Mb densities.
100-pin TQFP
DQ No. 1001
CE2), burst control inputs (ADSC\, ADSP\, ADV\), byte write enables
(BWx\) and global write (GW\).
• Operating Temperature Ranges:
- Military -55oC to +125oC
- Industrial -45oC to +85oC
*available as IT only.
IT
XT
Asynchronous inputs include the output enable (OE\), clock (CLK)
and snooze enable (ZZ). There is also a burst mode input (MODE) that
selects between interleaved and linear burst modes. The data-out (Q),
enabled by OE\, is also asynchronous. WRITE cycles can be from one
to two bytes wide, as controlled by the write control inputs.
Burst operation can be initiated with either address status processor
(ADSP\) or address status controller (ADSC\) inputs. Subsequent burst
addresses can be internally generated as controlled by the burst ad-
vance input (ADV\).
For more products and information
please visit our web site at
www.austinsemiconductor.com
Address and write control are registered on-chip to simplify WRITE
cycles. This allows self-timed WRITE cycles. Individual byte enables
allow individual bytes to be written. During WRITE cycles on this x18
device BWa\ controls DQa pins and DQPa; BWb\ controls DQb pins
and DQPb. GW\ LOW causes all bytes to be written. Parity bits are
available on this device.
ASI’s 4Mb Synchronous Burst SRAMs operate from a +3.3V VDD
power supply, and all inputs and outputs are TTL-compatible. The de-
vice is ideally suited for 486, Pentium®, and PowerPC systems and
those systems that benefit from a wide synchronous data bus.
GENERAL DESCRIPTION
The Austin Semiconductor, Inc. Synchronous Burst SRAM family
employs high-speed, low power CMOS designs that are fabricated us-
ing an advanced CMOS process.
ASI’s 4Mb Synchronous Burst SRAMs integrate a 256K x 18, SRAM
core with advanced synchronous peripheral circuitry and a 2-bit burst
counter. All synchronous inputs pass through registers controlled by a
positive-edge-triggered single clock input (CLK). The synchronous
inputs include all addresses, all data inputs, active LOW chip enable
(CE\), two additional chip enables for easy depth expansion (CE2\,
Austin Semiconductor, Inc. reserves the right to change products or specifications without notice.
AS5SS256K18
Rev. 2.0 12/00
1